Can't recommend any bottled nutrients after using salts (used cyco nutes years ago and Green planet before the move to salts), but there's a few additives that I think are good.
Fulvic acid is great, noticed plants were very vibrant looking when using it in my previous grows, it is a chelator which basically makes nutrients more available at broader pH ranges. Lots of minerals, vitamins and amino acids.
Pond Enzyme (Zyme) keeps roots clean, the enzyme breaks down dead and decaying matter which helps keeps bad bacteria at bay. Helps break down organic nutrients for increased bioavailability.
Monosilicic Acid, Orthosolicic Acid, Silicic Acid (Silica) for stronger stems, some say increases yield?? Way better but more expensive than Potassium Silicate though. Lots more benefits that I can't remember.
Natural PGR's (Plant growth regulators) like triacontanol enhance photosynthesis, cytokinins for increased cell division and larger roots.
Green planet's massive bloom has triacontanol.